The disclosure relates to a device for a hose, and more specifically a device for a double hose. For transfer of pumpable media at sea, such as for bunkering to platforms from supply ships or transfer of sludge from a platform to a supply ship, hoses that can float on water are used. For this purpose it is known to attach float elements on conventional hoses or to attach the tubular sheaths of foamed material to the hoses. Both of these hose assemblies provide buoyancy, but do not contribute to increase safety. Besides, these hose designs are not convenient and wear resistant.
In connection with the increased emphasis on the problems of pollution by emissions a need for safety beyond upgrade the dimensions of hoses has arisen.
Double hoses where the outer hose (cover hose) has been dedicated to capture leakage from the inner hose (main hose) have been suggested. Such safety hoses have provided the opportunity of designing hoses that float in water. But the main object of increasing safety has prevented creation of a satisfactory floating hose. For example, U.S. Pat. No. 6,085,796 (Riga, 2000) discloses a composite safety hose constituting an inner and an outer hose, which has been designed for hydraulic systems with low transportation capacity. The design of the end connections has not been satisfactory.
Double hoses with foam material in the outer annulus, a.o. to form thermal insulation, are also well known. Such a structure is described in U.S. Pat. No. 6,349,976 (Mentor Subsea, 2002), but this has not been suitable as floating hose.
Other known hose systems are described in Norwegian Patents Nos. 328 496 and 329 261. In the latter an inner and an outer hose employing a coupling element forming attachment for the main hose and cover hose is used, the free end of which is connected to a coupling element for connection to an external connection, said coupling element comprising an inner sleeve into which the end of the main hose is inserted for attachment, the inner sleeve being provided with threads at its free end for connection to a pipe system. The coupling element furthermore includes an outer sleeve attached to the cover hose and a connecting element for releasaable connection of the inner sleeve to the outer sleeve. Finally, the system of the mentioned patent includes a one-way valve allowing the emptying of the cover hose to the main hose.
The system has been shown to work excellent in the field of technology, but attaching the connecting element to the inner sleeve by means of screws has proven difficult. The problem is thermal expansion during welding. The inner sleeve has an ring-shaped extension comprising screw holes. This ring is typically welded onto the inner sleeve as part of the manufacturing process. The welding causes a thermal expansion which causes an inaccurate and often unsatisfactory positioning of the screw holes.